Method and apparatus for cutting elbow sections from pipe

ABSTRACT

Bends and elbows for use in larger size pipe, tube or conduit, such as circular and cylindrical sheet metal duct, for the purpose of installation normally come in several different stock sizes and angles and may be made from a series of sections or gores. The present method of making a section at a preselected angle is to place the pipe or tube from which the section is to be cut in a jig or fixture in proper alignment for rotation about a constant longitudinal axis, and while the pipe or tubing is rotating bring a cutting blade in cutting contact through the wall of the pipe while sustaining said blade in a movable gimbel or mounting corresponding to the angle desired. One form of the present machine comprises a wheeled base having a pipe or tubing jig thereon comprising adjustable arms which adjust radially from a center with end portions that are inserted inside the end of the tubing to hold same to rotate in alignment about a constant longitudinal centerline. A second jig or fixture may be used on the other end of the pipe if desired. An electric motor-driven circular cutting blade with a carbide edge is mounted in a fixed location on a pivotal frame which supports the blade against the wall of the pipe or conduit being cut and the angle of the support of the cutting blade is adjustable from a gear adjustment means. The pipe jig support is rotatably driven to rotate the pipe by means of a large circular gear which rotates the pipe while the cutting blade is making a cut at the desired angle and the cutting blade pivots to cut at an angle on the circular pipe or tubing.

United States Patent [72) Inventor Denver D. Saxon,

4384 Glenwood Parkway, DeKalb County,

near Decatur, Ga. 30032 [21] Appl. No 735,903 [22] Filed June I0, 1968(45] Patented June 29, I971 [54] METHOD AND APPARATUS FOR CUTTING ELBOWSECTIONS FROM PIPE 6 Claims, 15 Drawing Figs.

[52] US. Cl 82/47, 82/46, 82170.2 [51] Int.Cl B23b 1/00,

B23b 3/04, 82% 5/14 [50] Field of Search... 82/46, 47, 71, 72, 73, 74,75, 76, 77, 70.2

[56] References Cited UNITED STATES PATENTS 2,313,986 3/1943 B rown82/47 3,128,659 4/1964 Judelson 82/46 3,212,375 10/1965 Suizu 82/47 XFOREIGN PATENTS 564,587 10/1944 Great Britain 82/74 PrimaryExaminer-Harrison L Hinson Attorney-Patrick F. Henry ABSTRACT: Bends andelbows for use in larger size pipe, tube or conduit, such as circularand cylindrical sheet metal duct, for the purpose of installationnormally come in several different stock sizes and angles and may bemade from a series of sections or gores. The present method of making asection at a preselected angle is to place the pipe or tube from whichthe section is to be cut in a jig or fixture in proper alignment forrotation about a constant longitudinal axis, and while the pipe ortubing is rotating bring a cutting blade in cutting contact through thewall of the pipe while sustaining said blade in a movable gimbel ormounting corresponding to the angle desired. One form of the presentmachine comprises a wheeled base having a pipe or tubing jig thereoncomprising adjustable arms which adjust radially from a center with endportions that are inserted inside the end of the tubing to hold same torotate in alignment about a constant longitudinal centerline. A secondjig or fixture may be used on the other end of the pipe if desired. Anelectric motor-driven circular cutting blade with a carbide edge ismounted in a fixed location on a pivotal frame which supports the bladeagainst the wall of the pipe or conduit being cut and the angle of thesupport of the cutting blade is adjustable from a gear adjustment means.The pipe jig support is rotatably driven to rotate the pipe by means ofalarge circular gear which rotates the pipe while the cutting blade ismaking a cut at the desired angle and the cutting blade pivots to cut atan angle on the circular pipe or tubing.

METHOD AND APPARATUS FOR CUTTING ELBOW SECTIONS FROM PIPE BACKGROUND OFTHE INVENTION 1. Field of the Invention Pipe or conduit cutting methodsand apparatus. With respect to machines for cutting pipe, it should benoted that in the present machine the pipe rotates and remains in onelocation except for shifting to correspond with the angle being cut onthe circular surface of the pipe.

2. Description of the Prior Art The well-known art practiced in manysheet metal shops and the like of course is to use hand cutters such assnippers or compound shears to follow a line around the surface of thecylindrical tube to make the cut at the proper angle. There are alsomachines which use a reciprocating blade like a hacksaw blade which isset at an angle to the centerline of the pipe and then broughtsubstantially in a straight line through the pipe much as one would cutthrough a pipe at an angle with a hacksaw blade. The hand method isunsuitable for any type of production work as well as being difficultand producing uneven work. The reciprocating blade arrangement does notmake a contoured cut corresponding with the curvature of the exterior ofthe curved surface and would not be suitable for certain tubing or sheetmetal installations and assembly of elbows. The present method andapparatus among other things solves these problems by making an accuratecontoured cut through the surface of the pipe or tube and thereforecreates an angled end which is exactly correct for assembly into anelbow of a certain angle. Also, whereas some prior art methods andapparatus tend to dent or distort the cylindrical accuracy of the pipeor tubing, the present method and apparatus makes a clean accurate cutwithout any effective pressure which would distort the cylindricalshape.

SUMMARY OF THE INVENTION Pipe or tubing is accurately supported forrotation and alignment and a cutting means cuts through the surface ofthe pipe at a selected angle while the pipe is rotating. The machinecomprises a support means for removably supporting the pipe or tubinglength for accurate and aligned rotation about a fixed longitudinalcenterline and a cutting support means has a power-driven cutting bladethereon which cuts through the surface of the wall of the pipe at anangle contoured to correspond with the curvature of the pipe. Adjustmentmeans is provided for the support means for the pipe as well as forsetting and resetting the angle for the cut.

BRIEF DESCRIPTION OF THE DRAWINGS Objects, advantages, construction andoperation of a form of the invention will be apparent upon reading thefollowing specification taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a side elevation view of one form of the machine forpracticing the present method.

FIG. 2 is a enlarged front elevation view of the means for adjusting themachine to vary the pipe lengths.

FIG. 3 is a side elevation view of the adjustment means shown in FIG. 2.

FIG. 4 is a rear elevation view of the adjustment means shown in FIG. 2.

FIG. 5 is a cross-sectional view taken substantially along lines 5-5 inFIG. 1.

6 is a cross-sectional view taken substantially along lines 6-6 in FIG.1.

FIG. 7 is an enlarged plan view of the angle indicator of the adjustmentmeans for the cutting means.

FIG. 8 is an elevation view of the angle indicator shown in FIG. 7.

FIG. 9 is a rear perspective view of the machine shown in fig. 1 withoutany pipe therein.

FIG. 10 is an enlarged elevation view of the rotary cutting blade incontact with a tube or pipe to be cut.

FIG. 11 is a top plan view of the cutting means cutting support frameand cutting blade as the blade starts the cut.

FIG. 12 is a top plan view of the cutting means arrangement shown inFIG. II, as blade reaches of cut.

FIG. 13 is a top plan view of the cutting means arrangement shown inFIGS. 11 and 12 after the blade has reached the point of the rotation ofthe pipe and has shifted and is returning for the remaining 180 cut.

FIG. 14 is a top plan view of the cutting means arrangement shown inFIGS. Ill, 12, and 13 as blade 270 of cut.

FIG. 15 is a plan ofa section of elbow laid out flat to illustrate thecutting means shifting operation.

DESCRIPTION OF A PREFERRED EMBODIMENT It should be understood in readingthe following specification that the work is being performed on acylindrical pipe, tube or conduit which may be sheet metal or may beseamless metal or plastic tube or any other elongated, cylindricalC0nduit which has a wall thin enough to be cut. The present method andapparatus will cut any cylindrical conduit as long as the material canbe cut by a rotating carbide cutting blade or substitute arrangement.Therefore, when used throughout this specification the word pipe or tubeor cylindrical conduit are used interchangeably and do not refer to theparticular material or purpose for which the pipe, tube or conduit isbeing used. The purpose of the present. machine is to cut sections fromsuch pipe, tube or conduit and which sections may be used as part of anelbow or bend according to the angle the section has been cut by thepresent method and machine.

The machine is referred to generally and overall herein by referencenumeral 20 and performs its work on a piece of pipe, tube or conduit 22as referred to in the preceding paragraph.

Machine 20 comprises a frame means having a rectangular bottom supportframe 24 movably supported on wheels 26 whereby the entire machine 20may be moved by rolling from location to another. Frame 24 is made fromtubular stock bent into a rectangular shape having sides 28 and a frontend 30 and a rear end 32. Inclined frame members or plates 34 extendingupwardly from opposite sides of the machine at spaced locations supporta rotational pipe support means comprising longitudinal frame members 38of which there are several spaced radially. Longitudinally apaced,movable rings 40, 412 are attached to the members 38 and extendtherearound and are part of a rigid, cylindrical frame structure of thepipe support means which includes upper longitudinal angle iron framemembers 46 welded or otherwise secured to the rings 40, 42 which withthe frame members 38 and the supports 34 on the frame 28 provide amovable support means. The frame structure including rings 40, 42 andthe longitudinal tubes 38 and 46 are supported for rotation in bearingson the frame members on plates 34-.

A substantially solid, circular plate 50 on a ring 51 has radialopenings 52 therein supported for selective rotation for purpose ofadjustment only to select the starting position of the pipe about thelongitudinal centerline 5 4 in circumferentially spaced bearing members56 comprising channels 58 confining the edge of the plate 50 foraccurate rotation for adjustment therein. Plate 50 is normally fixed toring 51 to rotate therewith and part of the support means for the pipe22.

A large ring gear or slide gear or bull gear 60 is supported on andoutside the frame members 38, 56 and substantially transverse to thelongitudinal centerline 54 and is connected to the ring 40 to rotatesame. Gear 60 is driven by means of an electric motor 62 driving a drivegear 66 which meshes with the external gear surface of gear 60 which issupported in bearing channel members 70 having roller bearings 72therein.

The pipe support means includes a jaw or chuck arrangement comprisingfour pivoted arms 74 each pivoted at one end 76 to a plate 78 having acollar 80 to which is attached a shaft 82 that is the piston rod of apneumatic air cylinder device 84 controls from an air valve (not shown)from an air line 86. Each arm 74 is pivoted at the end opposite frompivot 76 on a pivot means intermediate a pipe support member 92 havingan end portion 94 inserted inside the open end of the pipe 22 andaligning and positioning same with the longitudinal centerline of pipe22 coincident with and in proper alignment with the centerline of thegear 60 and also aligned with a forward cutting support means 98comprising a ring member 100 which is pivotally mounted at the top andbottom on pivots 102, 104 on respective frame members 38, 46 so 180thering 100 will pivot substantially in the manner shown in FIGS. 11through 14, inclusive. The cutting support means 98 includes a part thatis shiftable fore and aft on a ring quadrant and bearing arrangement 106by means of a roller bracket assembly designated generally by referencenumeral 110 and shown in more detail in FIGS. 1 and 5. It is worthwhileto note that the ring 100 rotates with the pipe 22 inside the ring butthe ring 100 is shiftable to allow the set of the angle of the cut aswill appear hereinafter and also is movable on the pivots 102, 104 asshown in FIGS. 11 through 14, inclusive, to allow the cutting blade tomake the proper movement from the first one-half which is 180 of a 360cut determined by the complete rotation of the pipe 22. Reference toFIGS. 11 thru 15, illustrates that as the pipe rotates the cutting blade184, depending upon the angle to be cut, travels down the surface of thecylindrical pipe until it reaches the end of the first half of the cutat 180 whereupon the blade must reverse as shown in FIG. 11 thru 14,inclusive, in order to make the remaining 180 of the 360 travel. Theangle of the cut is determined by the angle of the plane diametric axisof the circumference of the blade 184 which is determined by anadjustment means 198.

The length of pipe is adjusted by an adjustment means 111 comprising arack 112 fixed along a frame member portion 114 and a gear 116 carriedby a shaft 118 mounted on a channel 120 which loosely engages one edgeof the ring 50 and the gear 116, the shaft 118, and the channel 120 aremovable with respect to the rack 112 on the member 114 so as to move theentire support means 50 to adjust the length of the pipe 22 along thecenterline 54 thereby to determine the amount of pipe which is fed to becut.

Another bracket 124 with a channel therein fitting around the peripheryof the plate 50 has a roller bearing 126 which engages the peripheralsurface of the plate 50 and assists in maintaining it in rotationalalignment. There is an identical adjustment arrangement 110 on the otherside of the machine carried on longitudinal frame member 46 andincluding the same corresponding rack 112, gear 116 and bracketarrangements 120, 124 with roller 126.

Both of the shafts 118 have a handle 130 thereon with a know 132 wherebythe handle may be rotated by hand to move the gear 1 16 in the teeth ofthe rack 112 thereby moving the entire ring 50 and all of the pipesupport means either forwardly or rearwardly along the centerline 54 toadjust the length of pipe which projects from the end of the machine.

The cutting means is designated generally by reference numeral 98 andreferring initially to FIG. 5 it will be seen that the ring 100 ismovable on the pivots 102, 104, as mentioned previously. Ring 100rotates within a floating cutting frame having angle iron braces whichare attached to bearing blocks 154 with wheels 155, there being fourwheels 155 spaced 90 apart around the circumference of ring 100. Thebottom of the ring 100 is supported in a bearing block 154 on a quadrantslide member 156 of arrangement 106 by means of a loose connection 158including a slide 160 which allows the ring 100 to rotate as well aspivot in the pivots 102, 104, as mentioned previously. However, theconnection 158 is loose by means of a wheel 162 sliding in the quadrantmember 156 to allow the relative movement adjustment of the plane of thecircumference of the face of the ring 100 with respect to the centerline54 through the pipe 22 as illustrated by the dotted lines in FIG. 1 andthe cutting frame 150. This is the means whereby the angle of the cutdesignated by reference numeral 164 is determined which determines theangle of the cut with respect to the centerline or pipe 22 and wherebythe blade 184 can move as the pipe 22 is cut.

The manually operated cutting means is designated generally by referencenumeral and it comprises a cutting arrangement including an arm 172 witha handle 174 and supported on a pivot 176 on one of the frame members150 as seen in FIG. 5. An electric motor 178 by means of a belt 180drives a pulley 182 having a circular cutting blade 184 attachedthereto. The center of the pulley 184 supports a bracket member on whichis rotatably attached a wheel 192 on a shaft 194. The periphery of wheel192 contacts the surface of the pipe 22 and determines the depth of thecut of the edge of the blade through the wall of the pipe 22 by limitingthe amount of penetration as shown in FIG. 10. Wheel 192 may be adjustedby adjusting shaft 194 in a slot 196 to increase or decrease the depthof cut of the edge of the blade 184 as required by the thickness of thewall of the pipe 22.

A means for setting the angle of cut is provided as seen in FIGS. 7 and8 in the form of an angle indicator arrangement designated generally byreference numeral 198 and comprising a fixed indexed pointed 2000 with atip 202 pointing to and reading adjacent a portion of an angle indicatoror protractor scale 204 which is fastened on a bracket 206 mounted withthe ring 100 and being pivotally mounted on a bolt pivot 208 through oneof the frame members 210 or 46. Starting at zero point when the ring isperfectly vertical with respect to'the centerline 54 the angle indicatorwill indicate 0 and then will be calibrated with angles indicated plusand minus in respective directions.

An alternative and additional support means for pipe 22 is representedby reference numeral 220 in general arrangement and is shown at theleft-hand side of FIG. 1 and comprises a floor support base 222 whichmay be constructed from angle iron or other material to make a rigidpillar support having a journal bearing portion 224 at the top thereofin which is mounted a bearing 226 having a hydraulic piston and cylinderarrangement 228 similar to the hydraulic cylinder 84 and including apiston rod 230 attached to a plate 232 carrying arms 234 similar to arms74 and arms 234 are connected at opposite ends respectively to plates232 and torespective jig, fixture or mandrel support arms 236 which haveeach of one respective end thereof pivotally connected at 238 to asupport plate 240 mounted with the bearing support portion 224. Theoperation of the pipe support 220 is substantially the same as theoperation of pipe support 78 both serving to position, align and supportthe ends respectively of the pipe 22 and to provide a quick, effectiveand simple manner both for attachment and detachment of the pipe. Theremay be times when the front end support arrangement 220 will not be usedany may not be located with the portable machine 20. However, there willbe times when it may be desirable to support the front end of the pipe22 as well as the inner or back end of the pipe. Both of thearrangements including the respective arms 92 and 236 act as retractableor moveable chucks or mandrels which move and pivot into and out ofposition in the inner end of the pipe 22.

After the proper angle has been selected for the cut on the pipe 22 asdetermined by the setting of the indicator 200 as mentioned previously,with reference to FIGS. 11 through 14, inclusive, it is seen that thecutting blade 182 which preferably has a diamond or carbide edge, restson the periphery of the pipe 22 starting at the top which is beinglooked down upon in FIG. 11. As the blade 184 rotates, the pipe 22 isrotated beneath the blade with the blade edge penetrating the wall ofthe pipe 22 as shown in FIG. 10. The blade which is carried by frame 150continues to cut as the frame 150 pivots in the respective pivots 104,102 which is necessary in order to permit the blade to shift from thefirst 90 through FIG. 12 until it travels the full 360 through FIG. 14making a out like that found in FIG. 15.

While I have shown and described a particular apparatus for cuttingelbow sections from pipe together with a suggested method for performingthis operation, this is by way ofillustration only and does notconstitute any sort of limitation on the scope of the invention asvarious alternations, changes, devia tions, eliminations, substitutions,additions, variations, omis sions, combinations and departures may bemade in the embodiment and the method shown without departing from thescope of my invention as defined by interpretation of the ap pendedclaims.

What I claim:

1. In a method for cutting tube or pipe and the like at a biased angleto the axis thereof, the steps comprising:

rotating the pipe to be cut about an axis substantially coincident withthe longitudinal centerline of the pipe and simultaneously with saidrotation bringing a cutting means into contact with said pipe anddirecting said cutting means in a path at a biased angle to the axisthereof corresponding to the biased angle cut on said pipe.

2. The method claimed in claim 1: said cutting means in eluding acutting blade having a cutting edge which is moved in an arcuate path.

3. The method of claim 2: said cutting blade being circular, saidcircular cutting blade being shifted about a diametric axis in onedirection as said pipe is cut the first of the are and then said bladebeing shifted in the opposite direction as the final 180 of are is cutin said pipe.

4. The method claimed in claim 1: said cutting means being mounted on amovable cutting frame, the cutting frame being shifted to compensate forthe change in direction when said pipe is cut at an angle.

5. The method of claim in claim 4: said cutting means being a rotatingcutting blade having a rotating cutting edge and the shifting of saidblade being about a. diametric axis of said blade.

6. The method claimed in claim 1: said cutting means being shiftedrelative to the longitudinal axis of the pipe being cut when saidangular cut on said pipe reaches the maximum in one direction to travelat the angle back to the starting place on the pipe.

1. In a method for cutting tube or pipe and the like at a biased angleto the axis thereof, the steps comprising: rotating the pipe to be cutabout an axis substantially coincident with the longitudinal centerlineof the pipe and simultaneously with said rotation bringing a cuttingmeans into contact with said pipe and directing said cutting means in apath at a biased angle to the axis thereof corresponding to the biasedangle cut on said pipe.
 2. The method claimed in claim 1: said cuttingmeans including a cutting blade having a cutting edge which is moved inan arcuate path.
 3. The method of claim 2: said cutting blade beingcircular, said circular cutting blade being shifted about a diametricaxis in one direction as said pipe is cut the first 180* of the arc andthen said blade being shifted in the opposite direction as the final180* of arc is cut in said pipe.
 4. The method claimed in claim 1: saidcutting means being mounted on a movable cutting frame, the cuttingframE being shifted to compensate for the change in direction when saidpipe is cut at an angle.
 5. The method of claim in claim 4: said cuttingmeans being a rotating cutting blade having a rotating cutting edge andthe shifting of said blade being about a diametric axis of said blade.6. The method claimed in claim 1: said cutting means being shiftedrelative to the longitudinal axis of the pipe being cut when saidangular cut on said pipe reaches the maximum in one direction to travelat the angle back to the starting place on the pipe.